Data from a modelling study on Arctic closure as a trigger for Atlantic overturning at the Eocene-Oligocene transition

David Hutchinson

This dataset was created for a study that investigates the effect of closing the Arctic-Atlantic gateway in a coupled climate model of the Eocene-Oligocene transition (EOT), 34 million years ago. This is motivated by proxy evidence of deep waters in the Labrador Sea becoming saltier and denser in the lead-up to the EOT. We find that closure of this gateway causes a transition from North Pacific deep water formation (as seen in the Eocene) to the start-up of North Atlantic deep water. This causes a cooling of the North Pacific, and a corresponding warming of the North Atlantic. The data are presented in netcdf format and represent 50 year averages at the end of the model spinup period. Monthly and annual averages are provided.

Citation

David Hutchinson (2019). Data from a modelling study on Arctic closure as a trigger for Atlantic overturning at the Eocene-Oligocene transition. Dataset version 1.0. Bolin Centre Database. https://doi.org/10.17043/hutchinson-2019

Data description

Data, in netcdf4 format, from five experiments in Hutchinson et al. (2019) are included in this dataset, provided in five corresponding data directories.

Two primary experiments:

- Control
- Arctic_closed

Three further perturbation experiments:

- GSR
- GSR_Arctic_closed
- SO_gateway

GSR denotes the 'shallow Greenland-Scotland Ridge' experiment, GSR_Arctic_closed is a combined shallow Greenland-Scotland Ridge with Arctic closed, and the SO_gateway experiment has wide Southern Ocean gateways, as described in the Methods section the paper.

For the primary experiments, both annual and monthly data are provided. For the ocean data fields, the monthly data is restricted to selected 2-dimensional fields that fluctuate more on seasonal timescales (e.g. Sea surface temperature and salinity, mixed layer depth), while the full 3-dimensional fields are provided only on the annual mean, due to space considerations.

Spinup time series for temperature and MOC (Meridional Overturning Circulation) indices for the two primary experiments are also included in their respective directories (as shown in Extended Data Figure 2 in the paper).